Merge branch 'gitlab-update-gpg' into 'master'

Update to GitLab 12.8.1 and use new rotated GitLab Public signing key

See merge request !8

12.8/Dockerfile

-ARG GITLAB_VERSION=v12.8.0-ubi8
+ARG GITLAB_VERSION=v12.8.1-ubi8
 
 ARG BASE_REGISTRY=registry.access.redhat.com
 ARG BASE_IMAGE=ubi8/ubi

12.8/scripts/prebuild.sh

@@ -2,7 +2,7 @@
 set -e
 
 ### Environment Variables ###
-GITLAB_VERSION=v12.8.0-ubi8
+GITLAB_VERSION=v12.8.1-ubi8
 VENDOR=gitlab
 
 
@@ -32,7 +32,7 @@ for server in $(shuf -e ha.pool.sks-keyservers.net \
                             hkp://keyserver.ubuntu.com:80 \
                             pgp.mit.edu) ;
 do
-    gpg --batch --keyserver "$server" --recv-keys 8040EEFCCED8C668EF27F7C61DC5606C0C7E9A9B && break || : ; \
+    gpg --batch --keyserver "$server" --recv-keys 5c7738cc4840f93f6e9170ff5a0e20d5f9706778 && break || : ; \
 done
 
 gpg --verify ${DOWNLOAD_DIR}/ubi8-build-dependencies-${GITLAB_VERSION}.tar.asc ${DOWNLOAD_DIR}/ubi8-build-dependencies-${GITLAB_VERSION}.tar